/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j.jmx;

//import java.lang.reflect.Constructor;
import java.util.Iterator;
import javax.management.DynamicMBean;
import javax.management.AttributeList;
import javax.management.Attribute;
import javax.management.RuntimeOperationsException;
import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.ObjectName;

import org.apache.log4j.Logger;

public abstract class AbstractDynamicMBean
		implements
			DynamicMBean,
			MBeanRegistration {

	String dClassName;
	MBeanServer server;

	/**
	 * Enables the to get the values of several attributes of the Dynamic MBean.
	 */
	public AttributeList getAttributes(String[] attributeNames) {

		// Check attributeNames is not null to avoid NullPointerException later
		// on
		if (attributeNames == null) {
			throw new RuntimeOperationsException(new IllegalArgumentException(
					"attributeNames[] cannot be null"),
					"Cannot invoke a getter of " + dClassName);
		}

		AttributeList resultList = new AttributeList();

		// if attributeNames is empty, return an empty result list
		if (attributeNames.length == 0)
			return resultList;

		// build the result attribute list
		for (int i = 0; i < attributeNames.length; i++) {
			try {
				Object value = getAttribute((String) attributeNames[i]);
				resultList.add(new Attribute(attributeNames[i], value));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return (resultList);
	}

	/**
	 * Sets the values of several attributes of the Dynamic MBean, and returns
	 * the list of attributes that have been set.
	 */
	public AttributeList setAttributes(AttributeList attributes) {

		// Check attributes is not null to avoid NullPointerException later on
		if (attributes == null) {
			throw new RuntimeOperationsException(new IllegalArgumentException(
					"AttributeList attributes cannot be null"),
					"Cannot invoke a setter of " + dClassName);
		}
		AttributeList resultList = new AttributeList();

		// if attributeNames is empty, nothing more to do
		if (attributes.isEmpty())
			return resultList;

		// for each attribute, try to set it and add to the result list if
		// successfull
		for (Iterator i = attributes.iterator(); i.hasNext();) {
			Attribute attr = (Attribute) i.next();
			try {
				setAttribute(attr);
				String name = attr.getName();
				Object value = getAttribute(name);
				resultList.add(new Attribute(name, value));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return (resultList);
	}

	protected abstract Logger getLogger();

	public void postDeregister() {
		getLogger().debug("postDeregister is called.");
	}

	public void postRegister(java.lang.Boolean registrationDone) {
	}

	public void preDeregister() {
		getLogger().debug("preDeregister called.");
	}

	public ObjectName preRegister(MBeanServer server, ObjectName name) {
		getLogger().debug(
				"preRegister called. Server=" + server + ", name=" + name);
		this.server = server;
		return name;
	}

}
